Drop end door balancer



Oct. 28, 1969 o. INGRAM 3, 7 7

' DROP END DOOR BALANCBR Filed larch 2, 1967 3 Sheets-Sheet 1 F T W l'p l FIG. 1

I L u k 6 1 4 FIG. 2 5 Inventor:

Orville lngr (1mv his Attorney 0. INGRAM DROP END DOOR BALANCER Filed larch 2. 196? 3 Sheets-Sheet 2 FIG.

1 I n v e n i o f Orville Ing ram his Affp rfne Oct. 28, 1969 o. INGRAM DROP END DOOR BALANCER 3 Sheets-Sheet v 5 Filed larch 2, 1967 FIG. 5

FIG. 7

FIG. 6

Inventor:

Orville lngr am his ALLunsx.

United States Patent C) 3,474,741 7 DROP END DOOR BALANCER Orville Ingram, Toledo, Ohio, assignor, by mesne assignments, to Midland-Ross Corporation, Cleveland, Ohio,

a corporation of Ohio Filed Mar. 2, 1967, Ser. No. 620,104 Int. Cl. B61d 17/06 US. Cl. 105-406 .12 Claims ABSTRACT OF THE DISCLOSURE A balancer for assisting in closing a drop end door of a railway gondola car having both main and compensating torsion springs, the former acting over the full range of movement of the door from open to closed position and the latter over a selected part of that range for minimizing differences over the range between the load of the door and the torque of the main spring.

Background of the invention Y As explained in my copending application on a selective drop end door balancer, Ser. No. 616,017 filed on Feb. 14, 1967, railway gondola cars are now proposed with drop end doors of such height and weight as not to be balanceable by a conventional balancer having one or more torsion springs acting over the full range of movement' of the door. It is to a solution of this problem that the present invention is particularly addressed.

Summary of the invention The improved gondola car drop end door balancer of the present invention provides an effective spring counter balance for assisting in closing both oversize and other end doors by combining main and compensating torsion springs which are energized as the door isopened but actover different ranges, the main over the full and the compensating over part of the range of movement of the door between open and closed positions, for holding within acceptable limits the dilierences between the sine load curve of the door and normally straight line torque curveof a torsion spring. As opposed to the balancer disclosed in my copending application, the compensating spring or springs are twisted at both ends with corresponding increase in their potential energy in the doors open posiiton. Additionally, the partial range of each of the one or more compensating springs is predeterminable and, preferably, the main and compensating springs are housed and the balancer is applied as a unit to and installable with the door.

The foregoing objectives, together with other objects and advantages of the invention, will appear hereinafter in the detailed description, be particularly pointed out in the appended claims and be illustrated in the accompanying drawings, in which:

Figure description FIGURE 1 is a rear elevational view of a drop end door and related structure of a railway gondola car incorporating a preferred embodiment of the improved balancer of the present invention;

FIGURE 2 is a fragmentary vertical sectional view on an enlarged scale of the structure of FIG. 1, taken along lines 2-2 of FIG. 3;

FIGURE 3 is a fragmentary vertical sectional view taken along lines 3-3 of FIG. 2;

FIGURE 4 is a fragmentary vertical taken along lines 44 of FIG. 2;

FIGURE 5 is a fragmentary vertical sectional view taken along lines 55 of FIG. 2;

sectional view 3,474,741 Patented Oct. 28, 1969 FIGURE 6 is a fragmentary vertical sectional view taken along lines 6-6 of FIG. 2; and

FIGURE 7 is a fragmentary vertical sectional view taken along lines 77 of FIG. 2.

Detailed description Referring now in detail to the drawings in which like reference characters designate like parts, the improved door balancer of the present invention is designed for application to drop end doors of railway gondola cars and particularly to the oversize doors now contemplated. Although oversize, such a door is conventional in being hinged at the bottom for swinging from a substantially vertical open position inward to a substantially horizontal position inside the car.

In illustrating the invention, a preferred embodiment of the improved balancer, designated as 1, has been applied to a drop end door 2 at one end of a body 3 of a railway gondola car (not otherwise shown). Conventionally, the door 2 is mounted on and between corner posts 4 at opposite corners of the adjoining end of the body 3 for hinging, swing or pivoting about a horizontal axis between a substantially vertical closed position and a substantially horizontal open position. Stopped, as usual, against outward swinging in its vertical position by engagement of its outer face 5 with end flanges 6 on the corner post 4, the illustrated door 2 has a body or body portion 7 of suitable configuration which terminates downwardly in a normally rearwardly directed, substantially horizontal bottom flange 8. This bottom flange and a generally U-shaped bottom member 9 welded or otherwise fixed or secured to and depending or extending below the flange and giving the door the preferred rounded bottom 10,

together form an open-ended, closed-sided housing 11 extending laterally of the car body across the bottom of the door. At opposite ends of the bottom member 9 are a pair of door brackets 12 having upstanding plate portions 13 riveted or otherwise fixed or secured to or rigid with the rear face 14 of the door body 7 and bosses or tubular or hollow portions 15 integral or rigid with the plate portions and fixed by welding to the adjoining ends of the bottom member. Each boss 15 has a cylindrical bore 16 substantially aligned longitudinally with and forming an extension of the hollow interior 17 of the housing 11 and preferably concentric or coaxial with the doors rounded bottom 10.

The door brackets 12 and a body bracket 18 associated with each and riveted or otherwise fixed or secured to the adjoining corner post 4, together hingedly connect the door 2 to the car body 3. While not unusual in this respect, the door and body brackets 12 and 18 are specially designed to suit them for their roles in the improved balancer of this invention. The bosses 15 of the door brackets 12 are the door parts or butts of the hinges 19 at the opposite sides of the door. The body parts or butts of these hinges are formed by exteriorly cylindrical hollow trunnions or stub axles 20 integral or rigid with and instanding laterally from the body brackets 18 into and rotatively received or journaled in the concentric or coaxial bores 16 of the bosses 15. However, instead of directly engaging, the door and body butts forming the hinge 19 at one and preferably each side of the door are spaced or separated by a concentric or coaxial cylindrical bearing, bushing or sleeve 21 which extends through and beyond opposite ends of the door boss 15 and is not only interposed between but also rotatable relative to both the boss and the trunnion.

The boss 15 has peripherally fixed or secured to its preferably cylindrical outer end portion 22 at the outer end thereof contiguous to the adjoining corner post 4,

a radially outstanding lever or crank arm 23 having on and integral or rigid with its outer face 24 a laterally or axially outstanding, suitably hook-shaped lug 25. The lever arm 23 conveniently is upright or substantially vertical in the closed position of the door 2 and in that position the lug 25 overlies or axially overlaps the part of the bearing 21 projecting outwardly beyond the boss 15. Extending crosswise or transversely of the outer face 24 of the arm 23, the lug 25 in the doors closed position has an upper or radially outer face 26 which desirably is arcuately convex and generally follows the contour of the periphery of the boss 15.

A driving connection between the boss 15 and the bearing21 for causing them to turn in opposite directions as the door 2 swings or moves between closed and open positions, suitably is provided by a cable 27 fixed at its inner end to and partially wrapping the bearing and having its outer end seated on and fixed, secured or anchored to the upper face 26 of the lug 25. Between its ends the cable 27 rides on and is reversed in direction or reentrantly looped or turned by a reversing idler pulley 28 mounted on or in the body bracket 18 forwardly of the lever arm 23 and radially outwardly of the bearing 21 for turning about an axis parallel to the hinging axis of the door.

The several elements forming the driving connection between the door bracket boss 15 and the bearing 21, preferably are protected from the elements by being housed within the related body bracket 18, the latter for the purpose having 9. preferably integral raised hood or enclosure 29 instanding or projecting inwardly from its base 30 and apertured to receive the outer end portion 22 of the boss. While the trunnion 20 is formed integrally or rigid with the base 30, an access opening 31 interrupting the base outwardly of the trunnion affords access for installation of the driving connection, the opening being closed by the adjoining corner post 4 when the bracket 18 is fixed in place. A bolt 32 extending through and supported at its ends in the hood 29 and the corner post 4, serves as a convenient mounting for the idler pulley 28.

As its main or full-acting torsion spring 33, the improved balancer 1 preferably has a multi-plate torsion bar housed by and extending through the housing 11 along the doors hinging axis and anchored at longitudinally spaced points to the door and the car body. The referred main torsion bar 33 has its outer ends anchored in the hollow trunnions 20 and, as in the door balancer of Goodwin Patent No. 2,580,760, issued Jan. 1, 1952, desirably is divided midway of those ends into two parts whose inner or adjoining ends are socketed or anchored in opposite sides of a door anchor member 34 mounted in and centered longitudinally on the housing 11. Turnable in the housing during installation and thereafter fixed in place, as explained in the patent, the central anchor 34 enables the normal torsion of the bar in the closed position of the door to be adjusted to suit the particular installation.

Depending on the additional torque required to compensate for the differences between the sine load curve of the door and the usual straight line torque plot or curve of the main torsion spring 33, the improved balancer may have one or, as illustrated, a pair or plurality of part-acting compensating springs 35 conveniently mounted in one end, if single, or, if a pair, in opposite ends of the housing 11. The or each compensating spring 35 preferably is a coil spring in torsion which encircles the main torsion bar 33 and is substantially centered on the doors hinging axis. Each coil spring 35 has a radially bent outer end 36 which is received and held or locked against relative turning in a notch or aperture in the inner end portion of the adjoining bearing 21. The opposite or inner end 38 of the spring is longitudinally or axially bent and received or seated in an arcuate slot 39 substantially concentric with the chefs hinging axis and formed in 4 an anchor plate 40 fixed in and extending transversely of the housing 11 normal to that axis and centrally apertured to pass the main spring 33.

It is by preselecting or predetermining the are or angular extent or length of the slot 39 and the normal position of the inner end 38 of the compensating spring therein in the closed position of the door 2; that the part of the full range of movement of the door betweeni closed and open positions, over which the spring will act, is selected or determined to suit the particular door. The intended action of the slot and the spring end therein in preselecting the compensating springs partial range of action is that of a lost motion connection between the door and the car body for rendering vthe compensating spring inactive or inoperative over a closed end portion of the range of movement of the door where an operator least needs assistance. The connection to'the door is directthrough the anchor plate buttorthe car body is indirect, since the bearing 21 to ,which'thc outer end 36 of the compensating spring 35 is directly connected itself is rotatable relative to both the door and the car body. Even so, the counter or opposite rotation of the bearing and the-door'as the latter moves by virtue of the driving connection between the bearing and the door boss 15 and the resultant definite relation between the torsioning and untorsioning of the spring and movement of the door relative to the'car body, in effect establishes a connection between the spring and the car As, during the initial movement of the door from closed position, the anchor plate 40 and inner end'38 of "the spring 35 in the slot 39 will countermove to'the extent of the lost motion in the slot, with their rates of rotation in the ratio of the radii from the fixed ends of the cable 27 to the doors rotative axis and, in the illustrated embodiment, the radius from the door-fixed end is the greater, the maximum lost motion 'for a slot of a given arc will be somewhat less than half of'the length of that are. Conversely, 'once the lost motion is consumed, the relatively higher rate of turning of the bearing 21 will produce a corresponding increasein the energizing of the spring over that possible ifthe rates were the same."

While the length of the slot 39 will impose'the maximum limit upon the lost motion obtainable in a particular in stallation, the obtaining of either that maximum or a lesser lost motion depends upon the position'o'f the inner spring end 38 in the slot in the closed or vertical position of the door. If, like the central anchor'34, 'the anchor plate 40 were adapted for initial rotation in the housing 11, it could be used for selectively positioning the spring" end in the slot. However, if, as in the illustrated embodi ment, the anchor plate is of such shape as not to be ro-" tatable in the housing, the burden of selectively position ing the inner spring end 38 in the slot 39 falls upon the bearing 21 and this burden it readily can support by being turned relative to the door bracket 12 before the cable 27 is fixed to it. Not only is the partial range of a cornpensatin'g spring so preselectable, but when, asin the illustrated embodiment, there are a pair of compensating springs, their preselected partial ranges can be the same or different as necessary to suit a particular installation.

In operation the main and compensating springs 33 and 35, over their respective ranges, are energized by opening of the door 2 and release that energy as the door is closed to assist in the closing. However, as opposed to the main spring, each compensating spring turns or twists at both ends relative to the car body 3, their inner ends 35 turning with the door and their outer ends 36 turning oppositely as their bearings 21 are driven by or drive the crank arms 23 on the door bosses 15 through the reversing cable 27.

As a consequence, the energy first imparted to and then returned by each compensating spring is far greater than if only one end were turned, morethan doubled in the illustrated embodiment.

From the above detailed description it will be apparent that there has been provided an improved end door balancer which, by using full range main and partial range compensating springs with provision for preselection of the partial range, provides effective counter-balancing of the load of even oversize doors. It should be understood that the described and disclosed embodiment is merely exemplary of the invention and that all modifications are intended to be included that do not depart from the spirit of the invention.

Having now described my invention, I claim:

1. A door balancer for a drop end door member hinged between sides of a body member of a railway gondola car for movement between a vertical closed position and a substantially horizontal open position comprising main torsion spring means acting between the members over the full range of movement of the door member between closed and open positions, means movable relative and drivably connected to the door member, and compensating spring means connected between the door member and said movable means for assisting said main spring means in closing the door member.

2. A door balancer according to claim 1, wherein the door member and movable means move in opposite directions on movement of the door member relative to the body member.

3. A door balancer according to claim 2, wherein the compensating spring means act over a part of the full range.

4. A door balancer according to claim 3, wherein the compensating spring means are lost motion connected to one of the door member and movable means.

5. A door balancer according to claim 4, wherein the movable means are rotatable relative to the door and body members and turned oppositely from the door member by the driving connection therebetween.

6. A door balancer according to claim 5, wherein the compensating spring means include a coil spring acting in torsion, the balancer including a body bracket fixed to the body member and a door bracket fixed to the door member and rotatably mounted upon said body bracket for hingedly connecting the door member at one side to the body member, and the movable means at said side is interposed between and rotatable relative to said brackets.

7. A door balancer according to claim 6, wherein the interposed rotatable means is a sleeve bearing connected to one end of the coil spring, and the driving connection between the compensating spring means and the door member at said side of the door member is a crank-andcable driving connection between the bearing and the door bracket.

8. A door balancer according to claim 7, wherein the crank-and-cable connection includes a crank arm fixed to the door bracket, a cable fixed at opposite ends to the bearing and said crank, and a pulley receiving and reversing the direction of said cable between said ends.

9. A door balancer according to claim 8, wherein the bearing is rotatable prior to the fixing of the cable thereto for predetermining the lost motion between the spring and the door member.

10. A door balancer according to claim 9, wherein the coil spring is housed in a bottom portion of the door member, and the bearing extends into and the crank, cable and pulley are housed in the body bracket.

11. A door balancer according to claim 10, wherein the coil spring has one end connected to the bearing, the balancer including an anchor plate fixed to the door member normal to a hinging axis thereof, and said anchor plate has an elongated arcuate slot substantially centered on the axis and receiving the opposite end of the coil spring for lost motion connecting the coil spring to the door member.

12. A door balancer according to claim 2, wherein the movable means turns both oppositely from and at a higher rate than the door member on movement of the door member between open and closed position for correspondingly increasing the energy releasable by the compensating spring means on closing of the door member.

References Cited UNITED STATES PATENTS 9/1951 Ingram l05-406.5 1/1952 Goodwin 406.5 

